Implantable stimulation devices deliver electrical stimuli to nerves and tissues for the therapy of various biological disorders, such as pacemakers to treat cardiac arrhythmia, defibrillators to treat cardiac fibrillation, cochlear stimulators to treat deafness, retinal stimulators to treat blindness, muscle stimulators to produce coordinated limb movement, spinal cord stimulators to treat chronic pain, cortical and deep brain stimulators (DBS) to treat motor and psychological disorders, and other neural stimulators to treat urinary incontinence, sleep apnea, shoulder subluxation, etc. The description that follows will generally focus on the use of the invention within a Spinal Cord Stimulation (SCS) system, such as that disclosed in U.S. Pat. No. 6,516,227. However, the present invention may find applicability with any Implantable Medical Device (IMD) or in any IMD system.
As shown in FIG. 1, a SCS system includes an Implantable Pulse Generator (IPG) 10 (hereinafter, and more generically, IMD 10), which includes a biocompatible device case 12 formed of titanium for example. The case 12 typically holds the circuitry and battery 14 necessary for the IMD 10 to function. The IMD 10 is coupled to electrodes 16 via one or more electrode leads 18 (two of which are shown). The proximal ends of the leads 18 are coupled to the IMD 10 at one or more lead connectors 20 fixed in a header 22, which can comprise an epoxy for example. In the illustrated embodiment, there are sixteen electrodes, although the number of leads and electrodes is application specific and therefore can vary. In an SCS application, two electrode leads 18 are typically implanted on the right and left side of the dura within the patient's spinal column. The proximal ends of the leads 18 are then tunneled through the patient's flesh to a distant location, such as the buttocks, where the IMD case 12 is implanted, at which point they are coupled to the lead connectors 20.
Cross sections of two examples of IMD 10, 10a and 10b, are shown in FIGS. 2A and 2B. Both contain a charging coil 24 for wirelessly charging the IMD's battery 14 using an external charging device (not shown). (If battery 14 is not rechargeable, charging coil 26 can be dispensed with). Both IMDs 10a and 10b also contain control circuitry such as a microcontroller 26, telemetry circuitry 28 (discussed further below), and various components 30 necessary for IMD operation, such as stimulation circuitry for forming therapeutic pulses at the electrodes 16. The charging coil 24, battery 14, microcontroller 26, telemetry circuitry 28, and other components 30 are electrically coupled to a printed circuit board (PCB) 32.
Different in the two IMDs 10a and 10b are the telemetry antennas 34a and 34b used to transcutaneously communicate data through the patient's tissue 36 with devices external to the patient (not shown in FIGS. 2A and 2B). In IMD 10a (FIG. 2A), the antenna comprises a coil 34a, which can bi-directionally communicate with an external device along a magnetic induction communication link 38a, which comprises a magnetic field of typically less than 10 MHz operable in its near-field to communicate at a distance of 12 inches or less for example. Telemetry circuitry 28a is electrically coupled to the coil antenna 34a to enable it to communicate via magnetic induction link 38a, and generally includes driver circuitry for energizing the coil antenna 34a to transmit data and amplifier/filter circuitry for resolving data received at the coil 34. Telemetry circuitry 28a generally also operates in accordance with a modulation scheme (defining how data to be transmitted is modulated on the link 38a and will be demodulated when received) and a communication protocol (defining the manner in which the data is formatted). Telemetry circuitry 28a receives the data to be transmitted in digital form from the microcontroller 26, and provides received digital data to the microcontroller 26 for interpretation. A typical modulation scheme used by telemetry circuitry 28a is Frequency Shift Keying (FSK), although other modulation schemes could also be used. In FIG. 2A, the external device would also contain communication means (e.g., a coil antenna; telemetry circuitry) compatible with the magnetic induction link 38a and the protocol used by the IMD 10a, as explained subsequently.
In IMD 10b (FIG. 2B), short-range Radio Frequency (RF) communication means—including short-range RF antenna 34b and compliant short-range RF telemetry circuitry 28b—are provided that operate in accordance with a short-range RF communication standard and its underlying protocols to bi-directionally communicate with an external device along a short-range RF communication link 38b. Short-range RF communication link 38b typically operates using far-field electromagnetic waves ranging from 10 MHz to 10 GHz or so, and allows communications between devices at distances of about 50 feet or less. Short-range RF standards supported by short-range RF telemetry circuitry 28b and antenna 34b include, for example, Bluetooth, BLE, NFC, Zigbee, WiFi (802.11x), and the Medical Implant Communication Service (MICS). Short-range RF antenna 34b can take any number of well-known forms for an electromagnetic antenna, such as patches, slots, wires, etc., and can operate as a dipole or a monopole. The external device in FIG. 2B would also contain short-range RF communication means compatible with short-range RF link 38b and the standard/protocols used in IMD 10b, as explained subsequently.
Although both of antennas 34a and 34b in IMDs 10a and 10b are shown in FIGS. 2A and 2B inside of case 12, they may also be placed within the IMD's header 22, or on the outside of the case 12. Although shown as exclusive in FIGS. 2A and 2B, an IMD 10 may have both of the different types of antennas 10a and 10b. 
Different configurations for external devices used to communicate with IMDs such as 10a and 10b exist in the prior art. Such external devices are typically used to send or adjust the therapy settings the IMD 10a or 10b will provide to the patient (such as which electrodes 16 are active to issue pulses; whether such electrodes sink or source current (i.e., polarity); the duration, frequency, and amplitude of pulses, etc.), which settings together comprise a stimulation program for the patient. External devices can also act as receivers of data from the IMD 10a or 10b, such as various data reporting on the IMD's status and the level of the IMD's battery 14.
An external device having such functionality is shown in FIG. 3 in the form of a patient remote control 40. Remote control (RC) 40 is typically hand-held, portable, and powered by a battery (not shown) within the RC's housing 41, which battery may be a primary battery or rechargeable. The RC 40 includes a Graphical User Interface (GUI) 43 similar to that used for a cell phone, including buttons 42 and a screen 44, and may have other interface aspects as well, such as a speaker. The RC 40 also includes within its housing 41 communication means, including a coil antenna 49a and/or a short-range RF antenna 49b, compatible with the link(s) 38a and/or 38b and the communication means in the IMDs 10a and/or 10b. Processing in the RC 40 is controlled via a microcontroller 46. As described above with respect to the IMDs 10a and 10b, antennas 49a and 49b would be associated with telemetry circuitry, although this is not shown in FIG. 3. One or more orthogonal coil antennas 49a driven out of phase could be used in RC 40 as well to improve communication coupling with the IMD 10a along magnetic induction link 38a, as discussed in U.S. Patent Application Publication 2009/0069869, with which the reader is assumed familiar.
Shown on the screen 44 in FIG. 3 are various options provided by the GUI 43 and selectable by a patient to control his IMD 10 (e.g. the stimulation program it is executing) or to monitor his IMD 10. Just a few typical options are depicted for simplicity that enable the patient to: start or stop stimulation; increase or decrease the amplitude of the stimulation pulses; check IMD monitoring information, such as the battery 14 level, operating status of the IMD, or other data telemetered from the IMD; etc.
Also shown in FIG. 3, and as disclosed in U.S. Pat. Nos. 8,498,716 and 8,588,925 which are incorporated herein by reference, an RC 40 can includes a port 45 on its housing 41, which may comprise a USB port for example. The '716 patent teaches that USB port 45 can be used to: recharge the RC 40's battery from a wall plug (assuming such battery is rechargeable); exchange data with another external device (such as an external computer; not shown); or couple to an external charging coil (not shown) to charge the IMD's battery 14 (assuming such battery 14 is rechargeable), in effect allowing RC 40 to operate as a combination RC/charger.
The '925 patent teaches that USB port 45 can be used to convey contraindication information—e.g., activities that might be counter-indicated for an IMD patient such as Magnetic Resonance Imaging (MRI) or some physical activity—to a person of interest, such as the patient or her clinician. In this regard, the '925 patent teaches that a cable can couple between port 45 on the RC 40 and a port on an external computer to allow contraindication information to be reviewed outside of the RC 40 itself Alternatively, the '925 patent teaches that a memory stick (not shown) may be coupled to port 45 to allow contraindication information resident in the RC 40 to be written to the memory stick, which memory stick can then be removed from the RC 40 and coupled to the external computer where the contraindication information can be reviewed.
External devices such as the RC 40 of FIG. 3 were historically built by the manufacturer of the IMDs, and thus were generally dedicated to communicate only with such IMDs. As such, dedicated RC 40 is not freely programmable by a patient, but is instead limited to the IMD functionality provided by the manufacturer. (However, the microcode operating in the RC's microcontroller 46 may be upgraded from time to time in manners specified by the manufacturer). However, there are many user-programmable commercial mobile devices, such as cell phones, that can provide GUIs and have inherent communication means suitable for functioning as a wireless external controller for an IMD.
FIGS. 4A and 4B show an example of a mobile device 50 configured for use as an external controller for an IMD, as described in commonly-owned U.S. Patent Application Publications 2015/0073498 and 2015/0231402, which are incorporated herein by reference. The mobile device 50 may be a commercial, multipurpose, consumer device, such as a cell phone, tablet, personal data assistant, laptop or notebook computer, or like device—essentially any mobile, hand-holdable device capable of functioning as a wireless external controller for an IMD. Examples include the Apple iPhone or iPad, Microsoft Surface, Nokia Lumia devices, Samsung Galaxy devices, and Google Android devices for example.
As shown in FIG. 4A, the mobile device 50 includes a GUI 53 with a screen 54, which may also receive input if it is a touch screen. The mobile device 50 may also have buttons 52 (e.g., a keyboard) for receiving input from the patient, a speaker 56, and a microphone 58. Mobile device 50 further includes a battery within its housing 51, although not shown, which battery may be a primary battery or rechargeable. Mobile device 50 can also include ports 55 and 57, which are subsequently explained. Mobile device 50 further includes at least one short-range RF antenna 59, again as subsequently explained, and would include telemetry circuitry compliant with that antenna(s), although not shown. Processing in the mobile device 50 is controlled by a microcontroller 61.
Shown on the screen 54 is a typical home screen GUI 53 provided by the mobile device 50 when first booted or reset. A number of applications (“apps”) 60 may be present and displayed as icons on the mobile device home screen GUI 53, which the patient can select and execute.
One of the applications (icons) displayed in FIG. 4A is a Medical Device Application (MDA) 70, which may reside as microcode in the mobile device 50's microcontroller 61. When MDA 70 is executed by the patient, the microcontroller 61 will configure the mobile device 50 for use as an external controller to communicate with an IMD. FIG. 4B shows the GUI 73 provided by the MDA 70 after it is executed, which includes options selectable by a patient to control his stimulation program or monitor his IMD, similar to what was described earlier with respect to the GUI 43 of the dedicated RC 40 of FIG. 3.
The MDA 70, like other applications 60 selectable in the mobile device 50, may have been downloaded using traditional techniques, such as from an Internet server or an “app store.” Although not strictly necessary, MDA 70 is logically developed and provided by the manufacturer of the IMD, and may be made available in different versions to work with different mobile device operating systems (e.g., iOS, Android, Windows, etc.). One skilled in the art will understand that MDA 70 comprises instructions that can be stored in the mobile device 50 or on an Internet server for example on non-transitory machine-readable media, such as magnetic, optical, or solid-state discs, integrated circuits, memory sticks, tapes, etc.
When the MDA 70 on the mobile device 50 is first selected and executed, or when an appropriate selection is made in the MDA, wireless communications with the IMD can be established using a communication means in the mobile device 50 and enabled by the MDA 70. The above-incorporated '498 Publication discloses different examples in which such communication can occur, illustrated here in FIGS. 5A-5C.
In FIG. 5A, the MDA 70 establishes wireless communication directly with the IMD 10b along short-range RF link 38b using short-range RF communication means supported by the mobile device 50 (e.g., WiFi or Bluetooth), including one of its short-range RF antennas 59 (FIG. 4A). In this instance, the IMD 10b would include short-range communication means compatible with short-range RF link 38b such as a short-range RF antenna 34b shown earlier with respect to FIG. 2B.
In FIG. 5B, a coil antenna 72 in a communication head 74 is coupled by a cable 76 to the port 55 on the mobile device 50, such as a USB port. In this example, the coil antenna 72 can be placed proximate to the IMD 10a to establish a magnetic induction link 38a, perhaps as modulated via FSK as mentioned earlier. The IMD 10a would include communication means compatible with magnetic induction link 38a such as a coil antenna 34a shown earlier with respect to FIG. 2A. The MDA 70 in this example would cause the mobile device 50 to issue and receive data at its USB port 55, which data may be modulated or digital depending whether the modulation/demodulation circuitry resides in the mobile device 50 or the communication head 74.
In FIG. 5C, the mobile device 50 communicates with the IMD 10a via an intermediary bridge 80. The bridge 80 contains first communication means including a short-range RF antenna 82b for wirelessly communicating with the mobile device 50 via short-range RF link 38b, and second communication means including a coil antenna 82a for wirelessly communicating with the IMD 10a via a magnetic induction link 38a. The bridge 80, which is preferably battery powered (battery not shown), essentially “translates” data on short-range RF link 38b into (FSK) data on magnetic induction link 38a, and vice versa. The MDA 70 can thus program the mobile device 50 to use its inherent short-range RF communication means (e.g., short-range antenna 59) to communicate with the IMD 10a, even if the IMD 10a is not compatible with such means, because the bridge 80 can translate and communicate with both. The communication system of FIG. 5C is further explained in U.S. Patent Application Publication 2013/0215285, which is incorporated herein by reference.
The '498 Publication further teaches that the MDA 70 can secure the mobile device 50 by controlling hardware and software that could affect, or worse corrupt, its use as an IMD external controller. Addressing such security issues is prudent because general-purpose commercial mobile devices by virtue of their broad connectivity are potentially subject to software viruses or tampering (“hacking”). For example, the '498 Publication discloses that the MDA 70 upon execution can temporarily configure the mobile device 50 to prevent operation inconsistent with external controller functionality, such as by disabling or reconfiguring hardware modules in the mobile device 50 that are either unnecessary or could potentially interfere with operation of the MDA 70. The MDA 70 can also terminate or temporarily suspend software tasks that might interfere with secure operation of the mobile device 50 as an external controller, such as other apps 60 displayable and executable from the mobile device home screen GUI 53 (FIG. 4A), or other software tasks that may run in the background of the mobile device in manners not immediately noticeable to the patient.
The above-incorporated '402 Publication describes other techniques for using a mobile device 50 to communicate with an IMD 10a or 10b, which are illustrated here in FIGS. 6A-6C. In these techniques, an accessory 90 with a connector 92 is coupled to an audio port 57 on the mobile device. The connector 92 and audio port 57 are co-axial, and typically comprise a left and right audio output signal, an audio input signal (MIC), and a ground. Typically a pair of headphones and/or a microphone (not shown) can be coupled to the audio port 57 on the mobile device 50 as is well known. Such signaling allows the accessory 90 to communicate bi-directionally with the mobile device 50. Additionally, the accessory 90 can receive power from the mobile device 50 for its circuitry via connector 92/audio port 57, or can include its own battery, as explained in the '402 Publication. Although not depicted here, the '402 Publication teaches that the accessory 90 can be coupled to a different type of port on the mobile device 50, such as the USB port 55.
In the '402 Publication, the accessory 90 is used to facilitate quick execution of the MDA 70 on the mobile device 50, essentially allowing a user instant access to GUI 73 to communicate with his IMD 10. In one example, the accessory 90 is used to immediately execute the MDA 70 on the mobile device, either upon pressing a switch 94 and/or when the accessory 90 is inserted into the audio port 57 and automatically validated by the mobile device 50. The accessory 90 can facilitate immediate execution of the MDA 70 by by-passing security measures inherent in the mobile device 50, such as screen locks or passwords, thus removing these encumbrances. The accessory 90 can further enable securing of the mobile device 50 for use as an IMD external controller, as explained above with respect to the '498 Publication. The use of the accessory 90 also provides a physical measure of IMD security, as the MDA 70 can be programmed to not execute if the patient's accessory 90 is not present and validated. Electronics in the accessory 90 are described in the '402 Publication but are largely omitted here.
In the example of FIG. 6A, once the MDA 70 is executed, communication with the IMD occurs using short-range communication means provided in the mobile device 50 itself, including at least one of its short-range RF antennas 59. This assumes use with an IMD (e.g., 10b) having a short-range RF antenna (e.g., 34b) compliant with the communication standard used by antenna 59.
If the IMD is not so compliant, other examples in the '402 Publication provide antennas in the accessories 90, as shown in FIGS. 6B and 6C. In FIG. 6B, the accessory 90 includes a coil antenna 96a capable of communicating with an IMB compliant with such communication means, such as IMD 10a of FIG. 2A. In FIG. 6C, the accessory 90 includes a short-range RF antenna 96b compliant with the IMD, such as IMB 10b of FIG. 2B. In this example, the accessory 90's short-range RF antenna 96b can communicate using a standard supported by the IMD 10b (e.g., MICS) which may not be supported by the short-range RF antenna 59 in the mobile device 50 (e.g., WiFi or Bluetooth). In either of the examples of FIGS. 6B and 6C, communications with the IMD 10a or 10b as controlled by the MDA 70 on the mobile device 50 occurs bi-directionally using the accessory 90's antennas 96a or 96b and the data path provided by audio port 57/connector 92. As such, the mobile device 50 in this example is only used for its easy provision of a GUI, rather than for its inherent communication capabilities (such as its non-compliant short-range RF antenna 59). Otherwise, the accessories 90 of FIGS. 6B and 6C provide the same benefits to security and ease of use provided by the accessory 90 of FIG. 6A.